It is well known to use an indazole as an antifoggant in a photographic developing composition. The indazoles have been used for this purpose in both black-and-white developing compositions and color developing compositions. Among the many patents disclosing such use are Peterson et al, U.S. Pat. No. 2,271,229 issued Jan. 27, 1942, which describes the incorporation of indazole antifoggants in both black-and-white and color developers; British Pat. No. 1,437,053 published May 26, 1976, which describes the use of indazoles as antifoggants in X-ray developers; and Sincius et al, U.S. Pat. No. 4,172,728, issued Oct. 30, 1979, which describes the use of indazoles as antifoggants in developers for graphic arts processes.
While the indazoles are very effective antifoggants, it is frequently necessary to utilize them at relatively high concentrations and, under such conditions, a serious problem arises in that they tend to undergo precipitation. This is particularly the case where a developing solution containing an indazole antifoggant is stored at relatively low temperatures. Under such conditions, it is common for the indazole to precipitate as a very fine crystalline material. This reduces the concentration of dissolved indazole which is available to provide antifoggant action and is also deleterious because the precipitate can adhere to the photographic film or paper and adversely affect its physical characteristics. In addition to temperature, there are other factors that affect the tendency for precipitation to occur, and it is believed that one such factor that is particularly important is the degree of purity of the indazole. Thus, for example, very pure indazole antifoggants are generally much less soluble than impure indazole antifoggants, since the impurities are capable of allowing preparation of solutions that are beyond their normal thermodynamic stabilities, i.e., that are both supersaturated and stable. However, the inevitable variation in the amount and type of impurities present means that there is an inherent instability problem associated with the use of indazole antifoggants. This lack of stability of developing compositions containing indazole antifoggants has seriously hampered their commercial utilization.
It is toward the objective of providing a stable photographic developing composition, in which an indazole is utilized as an antifoggant and in which there is little or no tendency for precipitation of the indazole to occur, that the present invention is directed.